qdGraphics

The initial purpose of the quick-and-dirty graphics library is to generate static images in Jupyter using a set of commands based on the primities in the Processing API. I wasn't particularly happy using Calysto-Processing (though its an impressive feat, don't get me wrong), since its variables don't persist from one cell to the next in Jupyter, and I don't have the patience and time to learn the matplotlib library right now, so I hacked this out this evening.

THIS DOCUMENTATION IS INCOMPLETE

So far the library supports the following:

Primitives

• ellipse(x, y, w, h). Draws an ellipse with top-left corner at (x, y) and with width diameter of w and height diameter of h.
• line(x1, y1, x2, y2). Draws a line from (x1, y1) to (x2, y2).
• polygon(points) (where points is a list of 2-tuples of 2D point coordinates). Draws a polygon with vertices given by points parameter.
• quad(x1, y1, x2, y2, x3, y3, x4, y4). Draws a quadrilateral with vertices (x1, y1), (x2, y2), (x3, y3), (x4, y4).
• rect(x, y, w, h). Draws a rectangle with (x, y) as the top left corner and w and h as the width and height.
• triangle(x1, y1, x2, y2, x3, y3). Draws a traingle through (x1, y1), (x2, y2), (x3, y3).

Shapes

More complicated shapes can be created via the following:

• beginShape(). Start a new shape.
• vertex(x, y). Add a vertex to the shape.
• endShape(close). Finish the shape. Setting close=True closes the polygon. The global variable CLOSE == True.
• beginContour(). Begin to define a secondary polygon for the shape, which is a hole. Once you call this, vertex modifies the current contour, not the outer shape. This should be specified in counter-clockwise order of vertices.
• endContour(). End the current contour.

Transformations

TODO

• pushTransform()/pushMatrix()
• popTransform()/popMatrix()
• translate(x, y)
• rotate(theta)

Style

TODO

• pushStyle()
• popStyle()
• fill(newFill)
• stroke(newStroke)
• strokeWidth(newStrokeWidth)

Setup and graphics context

• clear()
• size(w, h)

Example code:

from qdGraphics import *

clear()
size(300,300)

fill("yellow")
strokeWidth(3)

ellipse(50, 50, 40, 30)
line (20, 30, 90, 100)
poly = polygon([(60,20), (100,40), (100,80), (60,100), (20,80), (20,40)])
quad(100,40,60,100,20,80,20,40)
rect(0, 0, 25, 10)

pushStyle()
pushTransform()
translate(30, 0)
fill("red")
strokeWidth(1)
stroke("green")
beginShape()
vertex(150, 0)
vertex(75, 200)
vertex(225, 200)
beginContour()
vertex(150, 40)
vertex(160, 70)
vertex(130, 60)
endContour()
endShape(CLOSE)
popStyle()

popMatrix()
fill("orange")

rotate(20)
translate(65, 75)

beginShape();
vertex(-40, -40);
vertex(40, -40);
vertex(40, 40);
vertex(-40, 40);
beginContour();
vertex(-20, -20);
vertex(-20, 20);
vertex(20, 20);
vertex(20, -20);
endContour();
endShape(CLOSE);

draw()

Here's an animating example, but it's unsatisfactory in Jupyter because it pauses the interface and may not scroll properly.

from IPython import display
import time
from qdGraphics import *

x = 0

for i in range(100):
    clear()
    size(300, 300)
    ellipse(30+x, 30, 30, 30)
    x = x + 1
    display.clear_output(wait=True)
    display.display(draw())
    time.sleep(0.01)